Method and apparatus for aggregate-dispensing hopper conveyance and tracking

ABSTRACT

A dual-hopper aggregate spreader for spreading a layer of loose aggregate onto a road surface usually consists of a receiving hopper for the loose aggregate, and two (dual) second dispensing hoppers. In the preferred embodiment the conveyance of the dispensing hoppers is facilitated, in conjunction with other mechanical apparatuses, by a minimum of two conveyance glides, instead of rollers, gears, sprockets, etc., attached to a stationary frame that carries and aids in the conveyance of the dual dispensing hoppers, a minimum of two conveyance glides attached to the dual dispensing hoppers that then come into direct contact with the aforementioned frame glides, and, lastly, a minimum of two —one per side—tracking glides attached to the dual dispensing hopper&#39;s sides immediately adjacent and perpendicular to the conveyance glides.

PATENT CROSS-REFERENCES U.S. Patent Documents

6,161,986 December, 2000 Smith et al.

6,805,516 B2 October, 2004 Barnat et al.

BACKGROUND

1. The Field of the Invention

This invention relates to road construction and, more particularly, tonovel systems and methods for facilitating the spreading of looseaggregate onto a road surface.

2. The Background Art

Since the cost of roadways is substantial, it is desirable to lengthenthe useful life of a road as much as possible. To make roads lastlonger, they are sometimes treated for preventive maintenance.Preventive maintenance of a road surface can reduce the likelihood ofthe road surface becoming cracked or chipped, having potholes appear,and developing other similar problems that often occur with roads.

There are several ways that road surfaces can be treated to helplengthen the life of the roadway. Chip seals, also known as oil andscreenings, aggregate seal coats, and armor coats, are surfacetreatments which are placed on an existing asphalt pavement. Applying achip seal to a road is one form of preventive maintenance that can beused to increase the life of a roadway. Generally, the chip seals do notadd structural strength to the roadway, but they do produce an idealall-weather surface, renew weathered pavement, improve skid resistance,and seal the old pavement.

Chip seals are applied to a roadway by first spraying the pavement witha binder, often an asphalt emulsion, from an oil distributor truck. Thisbinder is a tacky coating placed onto the road surface that acts to bindgravel, to be applied soon thereafter, to the road surface. After thebinder is applied to the road surface, a uniform application of coveraggregate (similar to and including fine gravel) is applied, usually bya self-propelled chip spreader. For example, chip seals usually employ ¼to ½ inch (0.64 to 1.3 cm) aggregate. As the aggregate (i.e., gravel)contacts the sticky binder coat, it tends to stick to the road surface.The aggregate is usually rolled as soon as possible to ensure theadhesion of the aggregate to the binder and pavement surface.

There are many different designs and types of machines employed tospread the aforementioned aggregate as evenly as possible. Most, if notall of these machines are complex, requiring precision movements toensure the proper amount of aggregate is dispensed; for example, asdescribed and patented in U.S. Pat. No. 6,161,986. Many of thesemachines employ a hopper system, wherein the aggregate to be placed onthe road surface is first poured into a hopper or bin where it is thenevenly dispensed.

Some chip spreader designs employ dual, horizontally translatableaggregate-dispensing hopper systems where in two hoppers are loaded withaggregate and then the hoppers are moved into various positions todispense the aggregate, as diagrammed, but not patented, in U.S. Pat.No. 6,805,516 B2. Tremendous loads are oftentimes carried in thedispensing hoppers while the aggregate is temporarily contained therein.Such loads cause large stresses to many of the assemblies designed tomove or convey the hoppers into place so that the optimal amounts ofaggregate can be dispensed. In the past, most of these dual-hopperconveying systems employed rollers to bear the weight of the hopper. Dueto the localization of stresses to the roller/hopper contact surfaces,expensive materials were required in the manufacture of the rollershafts and bearing and tracking systems components. See detailed partslists and views of the various caster/shaft configurations employedindustry wide at www.geffs.com, www.ennyre.com and www.bearcatmfg.com.

BRIEF SUMMARY AND OBJECTS OF THE INVENTION

In view of the foregoing, it is a primary object of the presentinvention to provide an aggregate spreader dual hopper conveyance methodand apparatus to lessen the load per square unit localization ofstresses due to the use of rollers and/or gears. In employing theproposed invention, the conveyance of aggregate-dispensing dual hopperson chip spreaders will cost less due to less costly materials being usedto manufacture the conveyance assemblies. The reduction in cost can bepast along to the purchaser of these machines.

Another object of the present invention is to eliminate rollers and/orgears from being employed to convey aggregate-dispensing hoppers, andthus eliminate the common occurrence of one roller or gear shaftbreaking and/or malfunctioning and thus rendering an entire machinetemporarily inoperable.

In the preferred embodiment, the conveyance method and apparatus includea minimum of two glides attached to the stationary frame that carriesthe hoppers, a minimum of two glides attached to the hoppers that thencome into direct contact with the aforementioned frame glides, and,lastly, a minimum of two tracking glides attached perpendicularly to thehopper sides immediately adjacent to the aforementioned glides.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects and features of the present inventionwill become more fully apparent from the following description andappended claims, taken in conjunction with the accompanying drawings.Understanding that these drawings depict only typical embodiments of theinvention and are, therefore, not to be considered limiting of itsscope, the invention will be described with additional specificity anddetail through use of the accompanying drawings in which:

FIG. 1 is a perspective view of one possible embodiment of a dualaggregate spreader hopper system shown with the aggregate-dispensinghoppers supported by a stationary frame in a minimum widthconfiguration;

FIG. 2 is a perspective view of one possible embodiment of a dualaggregate spreader hopper system shown with the aggregate-dispensinghoppers supported by a stationary frame in a maximum widthconfiguration.;

FIG. 3 is a left side view of the aforementioned frame/hoppers systemillustrating the hoppers being supported by the frame;

FIG. 4 is a enlarged detail of FIG. 3 further showing the glides whichact as bearing surfaces attached to the frame, the glides which act asbearing surfaces attached to the movable hopper, and the glides whichact as tracking guides attached to the hopper sides;

FIG. 5 illustrates that the glides are attached to the entire length ofthe frame and moveable hoppers.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

It will be readily understood that the components of the presentinvention, as generally described and illustrated in the Figures herein,could be arranged and designed in a wide variety of differentconfigurations. Thus, the following more detailed description of theembodiments of the system and method of the present invention, asrepresented in FIGS. 1 through 5, is not intended to limit the scope ofthe invention, as claimed, but it is merely representative of thepresently preferred embodiments of the invention.

The presently preferred embodiments of the invention will be bestunderstood by reference to the drawings, wherein like parts aredesignated by like numerals throughout.

For the purposes of this invention, a “glide” is defined as an apparatusconsisting of a load bearing surface that comes in contact with anothersurface to provide limited part travel for one or both of the partsattached to the glide apparatus.

As shown in FIG. 1, chip spreader aggregate-dispensing hoppers (2) maybe configured as a dual hopper system suspended by a frame (1). If morethan one hopper is employed, the hoppers must be moved to variouspositions as shown in FIG. 2.

FIG. 3 Illustrates a side view of the frame (1) suspending the hoppers(2). FIG. 4 shows a detail of the contacting surfaces of the frame andhopper(s) which are often designed with gears or casters. As can bevisually discerned from FIG. 4, this invention eliminates theaforementioned gears or casters, and substitutes glides as thecontacting surfaces. The hopper (2) now makes contact with the frame (1)by a glide (3) attached to the hopper and a glide (4) attached to theframe. A third and fourth glide (5) act as tracking guides to keep thehopper on a demarcated path.

The advantage of such an invention is that instead of the full load ofthe hopper being distributed to the contacting surfaces of therelatively small tangents of the gears or wheels, and thus to therelatively small shafts that support the gears/casters, the load isevenly distributed to the entire contacting surfaces of the glides. Thiscan be the difference of a load contacting surface area of approximatelyone square inch supporting over 10,000 pounds, verses, in the case ofthis invention, a load contacting surface supporting a mere 40 poundsper square inch at maximum. As FIG A-A illustrates, the glides extendthe full lengths of the possible frame/hopper contact surfaces. Thus, asshown in FIG. 2 as a possible maximum width expansion scenario of thehoppers, the hoppers would contact from 100 percent to a minimum 50percent of the glides' contact surfaces. This invention would lendgreater stability, utilizing less moving parts and materials than anygear or caster conveyance system.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrative,and not restrictive. The scope of the invention is, therefore, indicatedby the appended claims, rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A method and apparatus to aid in the conveyance and keep a demarcatedpath of an asphalt resurfacing chip spreader aggregate-dispensinghopper(s) comprising: upper glides, lower glides, and tracking glides.